EP2403418B1 - Medical instrument - Google Patents

Description

The invention relates to a medical instrument with a hollow shaft, at the proximal end of which a handle consisting of at least two handle parts is arranged and at its distal end via a coupling mechanism, a tool tip can be fixed, which consists of at least two jaw parts, transversely to the instrument longitudinal axis angled tool wherein at least one jaw part of the tool for opening and closing via an adjustable handle portion of the handle against the at least one other jaw part of the tool is pivotable and the at least one pivotable jaw part and the corresponding, serving for pivoting of the jaw part handle part of the handle via an axial displaceable in the hollow shaft mounted pull / push rod are in operative connection with each other.

Generic medical instruments in which the pivotable jaw part, starting from a pivotable handle part of the handle via a pull / push element is actuated, find in particular in endoscopic surgery versatile use, such as punching, scissors, needle holder, barrel instruments and the like.

In the case of medical instruments in which the jaw parts of the tool are angled laterally relative to the instrument longitudinal axis, it is necessary to convert the axial movement of the pull / push rod initiated by the pivoting of the handle into a rotational movement. For this it is for example from the DE 103 27 655 A1 known to connect the train push rod and the pivotable jaw part via a transmission lever with each other. This constructive Implementation of the axial movement in a rotary motion has been well proven in practice, but this design is structurally very complex.

A comparable medical instrument according to the preamble is further from the DE 690 24 219 T2 (Basis for the preamble of claim 1) known, which proves to be less repair friendly and poor sterilizable.

Based on this, the invention has the object , a medical instrument of the type mentioned in such a way that the implementation of the axial movement of the pull / push rod in the rotational movement of the pivotable jaw with good power transmission is simple and reliable, while being easy to repair or sterilization friendly should.

The solution to this problem is inventively characterized in that each pivotable jaw part is connected to a proximally extending sleeve which is mounted rotatable about the instrument longitudinal axis and fixed in the axial direction in the tool tip and that the pull / push rod and each sleeve for pivoting of the respective pivotable jaw part via a pin-slot control in operative connection with each other.

Due to the inventive bearing of the at least one pivotable jaw part on a rotatably mounted in the tool tip sleeve, which in turn is connected via a pin-slot control with the pull / push rod in operative connection, it is possible in a structurally simple manner, the axial movement of the train / Convert push rod into a rotational movement of the sleeve and thus also of the pivotable jaw part.

In order to convert the axial movement of the pull / push rod as possible without play in a rotational movement of the sleeve, it is proposed according to a first embodiment of the invention that the pin-slot control consists of at least one stationary on the pull / push rod arranged control pin, the engages in a formed in each sleeve helical track.

According to the invention, it is proposed to provide a coupling mechanism between the hollow shaft and the tool tip and to form this as a bayonet connection. This designed as a bayonet coupling mechanism is characterized in that it is easy to handle and robust. The disengageability of the medical instrument into individual modular units due to the coupling mechanism facilitates the assembly and disassembly of the instrument for cleaning purposes, for sterilization purposes, for repair purposes and / or for changing the tool.

In order to secure the pull / push rod against torsion, the invention further proposes according to a preferred embodiment of the invention that in the region of the coupling mechanism on the pull / push rod at least one flat is formed, which with a corresponding contact surface on the inside of the Corresponding to the coupling mechanism having distal end of the shaft. In addition to the rotation, this causes at least one flattening on the pull / push rod together with the corresponding contact surface of the tool tip exact guidance of the pull / push rod in the axial direction.

According to a preferred embodiment, two opposing control pins are arranged on the pull / push rod, each engaging in a formed in each sleeve helical track to ensure uniform guidance of the pull / push rod and a smooth movement of the motion conversion.

According to a second, alternative embodiment of the invention it is proposed that the pin-slot control consists of a control pin which is fixedly arranged on each sleeve and which engages in each case in a helical guide track formed in the pull / push rod.

In order to reduce the friction between the sleeve rotatably mounted in the shaft and the shaft inner side or between two sleeves arranged coaxially with one another, it is proposed according to the invention that each sleeve has a lubricious coating on its outer jacket surface abutting on another component. Alternatively, it is of course also possible that the Shaft inside or sleeve inner side has on its sleeve adjacent to the inner circumferential surface a lubricious coating. Furthermore, it is possible to insert a sleeve made of a lubricious material between the components to be rotated relative to each other. As a lubricious material, for example, Teflon® or the like is advantageous.

According to a first practical embodiment of the invention it is proposed that a jaw part of the tool is rigid and the other jaw part of the tool is pivotable, wherein the rigid jaw part is connected to the tool tip and the pivotable jaw part is connected to the rotatably mounted in the tool tip sleeve. In this embodiment, the rigid jaw part, for example formed integrally with the tool tip, forms the distal end of the medical instrument according to the invention.

According to a second embodiment for the formation of the tool is proposed with the invention that both jaws of the tool are designed to pivot, each pivotable jaw part is connected in each case with a rotatably mounted in the tool tip sleeve and the two sleeves are coaxially mounted one inside the other.

Finally, it is proposed with the invention that the opening angle of the jaws to each other can be predetermined by the choice of the pitch of the helical guideway, so that depending on the application and required opening angle of the tool a sleeve with a corresponding helical pitch in the medical instrument according to the invention can be used.

The spiral pitch also plays a role in the effort required to open the jaws and at the speed with which the jaws are opened. Furthermore, can be on the arrangement of the helical guideway in the sleeve, namely from top to bottom from proximal to distal or vice versa, set whether the pivoting jaw part is opened or closed when opening or closing the handle.

To a possible backlash-free transmission of the rotational movement of the at least one rotatably mounted in the tool tip sleeve on the associated pivotable To cause jaw, the invention proposes that the pivotable jaw part and the sleeve, for example by means of gluing, rotationally connected to each other.

Fig. 1

eine schematische Seitenansicht eines erfindungsgemäßen medizinischen Instruments;

Fig. 2

eine perspektivische Explosionsdarstellung des Details II gemäß Fig. 1. eine erste erfindungsgemäße Ausführungsform von distal aus betrachtet darstellend;

Fig. 3

eine teilweise montierte Darstellung des Instruments gemäß Fig. 2, von proximal aus betrachtet und

Fig. 4

eine perspektivische Explosionsdarstellung des Details IV gemäß Fig. 1, eine zweite erfindungsgemäße Ausführungsform darstellend.

Further features and advantages of the invention will become apparent from the accompanying drawings, in which two embodiments of a medical instrument according to the invention are shown by way of example only, without limiting the invention to these embodiments. In the drawings shows:

Fig. 1

a schematic side view of a medical instrument according to the invention;

Fig. 2

an exploded perspective view of the detail II according to Fig. 1 , a first embodiment of the invention from distally viewed representing;

Fig. 3

a partially assembled view of the instrument according to Fig. 2 , viewed from the proximal and

Fig. 4

an exploded perspective view of the detail IV according to Fig. 1 FIG. 2 illustrates a second embodiment of the invention.

The illustration Fig. 1 shows a side view of a medical instrument 1, the power transmission mechanism can be used in many ways, such as for punching, scissors, needle holder, drum instruments and the like.

The medical instrument 1 shown essentially consists of a hollow shaft 2, at the proximal end of which is arranged a handle 3 a that is pivotable about a pivot axis 4 and a handle portion 3 b which is pivotable about a pivot axis 4. At the distal end of the shaft 2, a tool tip 6 can be fixed by means of a coupling mechanism 5, which tool comprises a tool 7 which is shown in FIGS Fig. 2 and 3 illustrated first embodiment of a rigid jaw part 7a and a relative to the rigid jaw part 7a pivotable jaw part 7b consists. At the in Fig. 4 illustrated second embodiment, the tool 7 consists of two mutually pivotable jaws 7b and 7c.

In the illustrated embodiments, the tool 7 is formed so that the jaw parts 7a, 7b and 7c are angled perpendicular to the instrument longitudinal axis 8: Other angular positions of the jaws 7a, 7b and 7c of the tool 7 to the instrument longitudinal axis 8 between 0 ° and 90 ° and also above however, they are also practical.

How to continue Fig. 2 to 4 can be seen, a pull / push rod 9 is mounted in the hollow shaft 2, which is the distal side with the pivotable jaw part 7b or the pivotable jaw parts 7b and 7c in operative connection and which is connected at the proximal end with the pivotable handle part 3b of the handle 3 to pass through the Swiveling the grip part 3b to transfer the pivotable jaw part 7b or the pivotable jaw parts 7b and 7c from a closed position to an open position or vice versa.

The dismantling of the medical instrument 1 in individual modular units, such as the tool tip 6 and the shaft 2, facilitates the assembly and disassembly of the medical instrument 1 for cleaning purposes and / or for changing the tool 7. In the illustrated embodiments, the coupling mechanism 5, over which the tool tip 6 on the shaft 2 can be fixed, designed as a bayonet connection.

In order to convert the actuation of the pivotable handle part 3b of the handle 3 on the pull / push rod 9, acting solely in the axial direction displacement of the pull / push rod 9 in a rotational movement for pivoting the pivotable jaw parts 7b, 7c of the tool 7 to convert is each pivotable jaw part 7b, 7c rotationally connected to a proximally extending sleeve 10 which is rotatable about the instrument longitudinal axis 8, but fixed in the axial direction in the tool tip 6, wherein the pull / push rod 9 and each sleeve 10 for pivoting the pivotable jaw parts 7b, 7c via a pin-slot control 11 are in operative connection with each other.

The pin-slot controller 11 consists in the illustrated embodiments of two oppositely fixed to the pull / push rod 9 arranged control pin 12, which engage in each case formed in each sleeve 10 helical guide track 13. Of course, the use of only one control pin 12 and a helical guideway 13 is sufficient, but two control pins 12 provide better guidance of the pull / push rod 9 and a smooth movement of the motion conversion of the translational to the rotational movement.

As an alternative to the previously described embodiment of the pin-slot control 10, it is also possible to arrange a stationary control pin 12 on the sleeve 10, which engages in each case a helical guide track 13 formed in the pull / push rod 9.

These pin-slot controls 11 designed as described above cause the control pin 12 of the pull / push rod 9 engaging in the helical guideways 13 in the axial direction to displace the sleeves 8 mounted in the tool tip 6 in the axial direction Turn instrument longitudinal axis 8, which in turn causes a pivoting of the sleeve 10 connected to the pivotable jaw parts 7b, 7c of the tool 7.

By selecting the pitch of the helical guide tracks 13, the opening angle of the jaw parts 7a, 7b and 7c can be predetermined to each other, so that depending on the application and required opening angle of the tool 7, a sleeve 10 with a corresponding helical pitch in the tool tip 6 of the medical instrument 1 can be used.

The choice of the helical pitch also plays a role in the force required to open the jaws 7b, 7c and at the speed with which the jaws 7b, 7c are opened. Furthermore, can be on the arrangement of the helical guideways 13 in the sleeve 10, namely from top to bottom from proximal to distal or vice versa, set whether the opening or closing of the handle 3, the pivotable jaw parts 7b, 7c are opened or closed.

To the friction between the rotatably mounted in the shaft 2 sleeve 10 and the shaft inner side or between two coaxially mounted sleeves 10 (FIGS. Fig. 4 ), it is advantageous to provide each sleeve 10 with a lubricious coating on its outer jacket surface 10a adjacent to the inner side of the shank or inner side of the sheath. Alternatively, it is also possible for the inner side of the shank or inner side of the sheath to have a lubricious coating on its inner circumferential surface lying against the sleeve 10. Furthermore, it is possible to insert a sleeve made of a lubricious material between the components to be rotated relative to each other. As a lubricious material, for example, Teflon® or the like is advantageous.

In order to secure the pull / push rod 9 against torsion, at least one flat 14 is formed in the region of the coupling mechanism 5 formed as a bayonet connection on the pull / push rod 9, which has a corresponding contact surface 15 on the inside of the tool tip having the coupling mechanism 6 corresponds. In addition to the rotation, this guarantees at least one flat 14 on the pull / push rod 9 together with the corresponding contact surface 15 of the tool tip 6 an exact guidance of the pull / push rod 9 in the axial direction.

The two in the pictures Fig. 2 and 3 as in Fig. 4 illustrated medical instruments 1 differ from each other by the formation of the tools 7, namely in a tool 7 with a rigid jaw part 7a and a pivotable jaw part 7b according to Fig. 2 and 3 and in a tool 7 with two mutually pivotable jaws 7b and 7c according to Fig. 4 ,

At the in Fig. 2 and 3 The first embodiment shown, the rigid jaw part 7a is fixedly connected to the tool tip 6, while the pivotable jaw part 7b rotationally fixed to the sleeve 10 is connected, which is rotatably mounted in the tool tip 6 in the mounted state. The rotationally fixed connection of the sleeve 10 with the pivotable jaw part 7b, for example, by gluing or positive connection of the two components 7b and 10, wherein in the illustrated embodiment on the sleeve 10, a pin 16 is formed on the distal side in the assembled state in a corresponding receptacle 17th engaged in the pivotable jaw part 7b.

At the in Fig. 2 and 3 In the illustrated embodiment, the tool tip 6 consists of two parts, a distal part 6a having the jaw parts 7a and 7b, and a proximal part 6b having the coupling mechanism 5. The two parts 6a and 6b of the tool tip 6 are connected to each other, for example by welding.

For mounting the in Fig. 2 and 3 1, the pull / push rod 9 is first pushed proximally through the proximal part 6b of the tool tip 6 until the pull / push rod 9 is received in the sleeve 10. In this position, the control pin 12 is inserted into the pull / push rod 9, that the control pin 12 forming the pin-slot control 11 engages in the two formed in the sleeve 10 helical guideways 13.

Subsequently, the pivotable jaw part 7b is inserted through a recess 18 in the tool tip 6 and the coupled with the pull / push rod 9 sleeve 10 inserted into the distal part 6a of the tool tip 6 until the pin 16 of the sleeve 10 in the receptacle 17 of the pivotable Jaw part 7b engages.

In the subsequent assembly step, the proximal part 6b and the distal part 6a of the tool tip 6 are connected to one another and in the last step the tool tip 6 and the shaft 2 are coupled to one another via the bayonet connection.

At the in Fig. 4 illustrated second embodiment, the tool 7 consists of the two mutually pivotable jaw parts 7b and 7c, which are each connected to a rotatably mounted in the tool tip 6 sleeve 10, wherein the two sleeves 10 mounted in the assembled state coaxially with each other and rotatable against each other in the tool tip 6 are.

The rotationally fixed connection of the sleeves 10 with the pivotable jaw parts 7b and 7c, for example, by gluing or positive connection of the two components 7b and 10 or 7c and 10th

At the in Fig. 4 In the embodiment shown, the tool tip 6 also consists of two parts, a distal part 6a having the jaw parts 7a and 7b and a proximal part 6b having the coupling mechanism 5. The two parts 6a and 6b of the tool tip 6 are connected to each other for example by screwing.

For mounting the in Fig. 4 1, the pull / push rod 9 is first pushed proximally through the proximal part 6b of the tool tip 6 until the pull / push rod 9 is received in the two coaxially telescoped sleeves 10. In this position, the control pin 12 is inserted into the pull / push rod 9, that the control pin 12, the pin slot controller 11 forming, engages in each of the two formed in the sleeves 10 helical guideways 13.

Subsequently, the pivotable jaw parts 7b and 7c are inserted via a recess 18 in the tool tip 6 and the coupled with the pull / push rod 9 sleeves 10 inserted into the distal part 6a of the tool tip 6 until the sleeves 10 against rotation with the pivotable jaw parts 7b and 7c are connected.

In the subsequent assembly step, the proximal part 6b and the distal part 6a of the tool tip 6 are connected to one another and in the last step the tool tip 6 and the shaft 2 are coupled to one another via the bayonet connection.

The thus formed medical instruments 1 are characterized by the fact that the pure axial movement of the pull / push rod 9 is simply and easily dosed and substantially free of play converted into a rotational movement of the jaws 7b and 7c by the described pin-slot control 11.

LIST OF REFERENCE NUMBERS

1 medical instrument 10a lateral surface 2 shaft 11 Pin-slot-control 3 handle 12 control pin 3a rigid handle part 13 guideway 3b pivotable handle part 14 flattening 4 swivel axis 15 contact surface 5 coupling mechanism 16 spigot 6 tool tip 17 admission 6a distal part 18 recess 6b proximal part 7 Tool 7a rigid jaw part 7b swiveling jaw part 7c swiveling jaw part 8th instrument longitudinal axis 9 Pull / push rod 10 shell

Claims (11)

1. Medical instrument with a hollow shaft (2), at the proximal end of which a handle (3) consisting of at least two grip parts (3a, 3b) is arranged and at the distal end of which a tool tip (6) can be fixed, the tool tip having a tool (7) which consists of at least two jaw parts (7a, 7b) and is angled transversely with respect to the longitudinal axis (8) of the instrument, wherein at least one jaw part (7b) of the tool (7) can be pivoted with respect to the at least one other jaw part (7a) of the tool (7) for opening and closing by way of an adjustably designed grip part (3b) of the handle (3), and the at least one pivotable jaw part (7b) and the corresponding grip part (3b) of the handle (3) which serves to pivot the jaw part (7b) are operatively connected to one another by way of a pull/push rod (9) mounted in an axially displaceable manner in the hollow shaft (2), wherein each pivotable jaw part (7b) is connected to a sleeve (10), which extends towards the proximal end and which is mounted in the tool tip (6) such that it can be twisted about the longitudinal axis (8) of the instrument and is fixed in the axial direction, and wherein the pull/push rod (9) and each sleeve (10) are operatively connected to one another to pivot the relevant pivotable jaw part (7b) by way of a pin-and-slot control (11),
   characterized
   in that a tool tip (6) can be fixed to the distal end of the hollow shaft (2) by way of a coupling mechanism (5),
   and in that the coupling mechanism (5), by way of which the tool tip (6) can be fixed to the shaft (2), is in the form of a bayonet connection.
2. Medical instrument according to Claim 1, characterized in that at least one flattened portion (14) is formed on the pull/push rod (9) in the region of the coupling mechanism (5), and corresponds to a corresponding contact surface (15) on the inner side of the tool tip (6) having the coupling mechanism (5), in order to secure the pull/push rod (9) against torsion.
3. Medical instrument according to Claim 1 or 2, characterized in that the pin-and-slot control (11) consists of at least one control pin (12), which is arranged fixed in position on the pull/push rod (9) and engages into a helical guideway (13) formed in each sleeve (10).
4. Medical instrument according to Claim 3, characterized in that two control pins (12) which lie opposite one another and each engage into a helical guideway (13) formed in each sleeve (10) are arranged on the pull/push rod (9).
5. Medical instrument according to Claim 1 or 2, characterized in that the pin-and-slot control (11) consists of a control pin (12), which is arranged fixed in position on each sleeve (10) and engages into in each case one helical guideway (13) formed in the pull/push rod (9).
6. Medical instrument according to one of Claims 1 to 5, characterized in that each sleeve (10) mounted in the tool tip (6) such that it can be twisted has a coating with slip properties on the outer lateral surface (10a) thereof which bears against another component (6 or 10).
7. Medical instrument according to one of Claims 1 to 6, characterized in that one jaw part (7a) of the tool (7) is formed so as to be rigid and the other jaw part (7b) of the tool (7) is formed so as to be pivotable, wherein the rigid jaw part (7a) is connected to the tool tip (6) and the pivotable jaw part (7b) is connected to the sleeve (10) mounted in the tool tip (6) such that it can be twisted.
8. Medical instrument according to one of Claims 1 to 6, characterized in that both jaw parts (7b, 7c) of the tool (7) are formed so as to be pivotable, wherein each pivotable jaw part (7b, 7c) is connected in each case to a sleeve (10) mounted in the tool tip (6) such that it can be twisted, and the two sleeves (10) are mounted coaxially one inside the other.
9. Medical instrument according to one of Claims 3 to 8, characterized in that the opening angle of the jaw parts (7a, 7b) in relation to one another can be predetermined by the selection of the pitch of the helical guideway (13).
10. Medical instrument according to one of Claims 1 to 9, characterized in that the at least one pivotable jaw part (7b) and the associated sleeve (10) are connected to one another such that they cannot twist.
11. Medical instrument according to Claim 10, characterized in that the at least one pivotable jaw part (7b) and the associated sleeve (10) are adhesively bonded to one another.

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